I have a single SkeletalMesh and two animations for it. Running it on HTML5 works just fine with a reasonable frame rate. However, running my game on Android (HTC One, see specs), it is not playable.
When importing my SkeletalMesh as StaticMesh, the FPS is around 38. When using it as a SkeletalMesh, the FPS is around 8. So there is a frame rate drop of 30 just because my mesh has a skeleton instead of not having one? After all it is has the same polycount, materials, etc. …
Is there anything I can do to prevent this frame rate drop?
Have you checked the content creation for mobile platforms documentation with regards to mesh limitations? It addresses the limitations for skeletal meshes specifically. Have a look and see if yours exceeds these.